Air-feed brake for rock drills



JmL/6, 1925. l f 1,522,336y y F. M. SLATER Am FEED BRAKE FOR Rock D'RILLs Filed oct. 12, 1922 INVENToR 'X fdMJ/azz Patented Jan. 6, 1925i.

U NITED YSTAT-ES PATENT Oife-rijen.

FEED M. sLATER., OE EASTON, PENNSYLVA'N11i, AssIGNOE `To1:INdEiasoLL-mmn COMPANY, or JERSEY CITY,` JERSEY, yn CORPORATION OF NEW JERSEY.

AIR-FEED BRAKE FOR ROCK DRILLS.

Application led October 12, 1922. Serial N 0. 593,946.

To ZZ whom/'it may concern:

Be it known that I, FRED M. SLATER, a citizen of theUnitedStates, and -a resident of Easton, county ofU Northampton, land State of Pennsylvania, haveinvented a certain Air-F eed Brake. for Rock VlDrills, of which the followingfis a specicat'ionaccompanied by drawings.k Y v 'This invention 'relates-to 4fluid vactuated rock drills,but more particularly to 'a brake for controlling the lfeeding element ofV .a stope drill, although thefinveiition may be applied to any drillhaving a fluid actuated feeding'element. I

The Objects ofthe'invention are torenable the members of-the fluid actuatedfeeding element of a stopedrill for instance, to be positively locked agai-nstrelative movement when desired, or to enable a braking effect to be applied to the air feeding element in such manner that the forwardfeed of the machine may be checked or slowed down without actually lockingv the members against movement.

Another Object of the invention isto securean efficient braking Vdevice `for theifeeding element automatically controlledV in accordance ywith the resistance to rotation encountered by the drill steel,in an automati- 'cally rotatedrock drill. d

' Theinv'ention is illustratedin the accompanying drawings, in which-` i V`ld`igure lis--a longitudmalsectional elevationiof a stope'drill embodying.,the/invention, Y Figurer? is? a transverse sectional viewi on the wline 2-2 of Figure 1,?looking'in lthe direction of the arrows,and

Figure 3 Vis a transverse sectional view ,of Figure 1 on the line l@9i-f3,looking in the direction of the arrows.

Referring tol the drawings, the invention isillustrated in connection with a stope drill Vof the hammertype having automatic rotation for the ydrill steel .AQ in this'instance rifle Abar rotation being shown. vThe cylinder Ahas a reciprocating pistonB formed Ywith a fluted forward extension C which imparts blows of impact to theanvil block Vl) through which the blows are imparted to 'the drill steel A. The .shank of the drill steel extends intov the chuck'E carried in kthe yfront headF and a front cylinder washer Gfis interposed between the front head F andthe cylinder A. The chuck E is connected to the chuck sleevel H having the chuck nut J to which parts rotation isimparted by therotating. piston B. The piston has the usual rifle .nut K engaging therifle bar L which `carries the rotation ratchet O having the v'usual pawls l) adapted to engage the rotation lratchetY ring Q, in the back head R.

A head block vSi is interposed between the feed cylinderhe'ad- T Aand the back headR, and the feeding element comprises two movable members consisting ofthe feed cylin* der U and thepiston V having the piston rod l/V provided with the rock engaging pointer X. The 4feeding element piston rod lV is preferably in vnon-rotatable engagement with'the cylinder'Uand for this purpose, the piston rod'may beprovided with the longitudinal-:groove Y. engaging arib Zion-thejcylinden` Y s The head block S ofthe rock drill is provided .withv the yusual ,handle a commonly called the rotation handle, which is adapted to bev grasped'by the'hand'of'tlie operator during the drilling operation; Fluid pressure is supplied'to the machine through the -inlet o in the back headR controlled by a suitable throttle valve 4c.' .From the throttle valve a passage ZA ei'ctendsv through the back head R, head block S and feed cylinder head T, tothe feed' 'cylinderfor supplying fluid pressure to thefeeding element. The parts ofthe machine comprising ythe casing are adaptedto be held together by suitableV side'bolts, not shown. The" braking' device for the feeding element inv this instance inchicles a' longitudinally movable and rotatable member, which may be in the form of a'brake'rod e' having aV screw threaded shank j' engaging a threaded sleeve g held' within the feed pistonV. and preferably serving to connect thelpiston to the piston rod W, as

by means of thethreads L'. 1interposed between'the head fof. the brake rod e and the feed cylinderhe'guilv T are two series of relatively 'longitudinally movable brake discs, one seriesof discsc being keyed tothe feed cylinder head T, as by means of theribs o, and the other series of dises 79 being keyed to vthe rotatable brake rod e as by means of' the key'q. A partition 7' is provided in the head bl'ock'S fOr-ming a pressure chamber t and a flexible diaphragm u is preferably located in said chamber Overa button or plunger c which extends through the partition y" and is adapted to bear .upon the head j of the brake rod e. Fluid pressure applied to the chamber t above the diaphragm u will depress the plunger e and force the head j of the brake rod e down upon the braking discs 7c and p thus pressing said discs together and checking 'or preventing rotation of the brake rod c according to the pressure applied to the diaphragm u. As the brake rod e is adapted to move longitudinally with the feed cylinder U and at the same time rotate, it is obvious that the feeding of the machine may be controlled by con trolling the freedom of rotation of the brake rod.

In order to automatically control the rotation of the brake rod, and the application of the brake in accordance with the resistance to rotation of the drill steel A', I prefer to provide a valve w in the back head R controlling fluid passages m and y leading from the throttle valve c to the pressure chamber t above the diaphragm u and I provide means for actuating said valve w. from the rotation ratchet ring Q. For this purpose, the ratchet ring Q, is provided with an arm or finger e extending into the valve chamber 2 and adapted to bear upon the end 3 of the valve lw, so that when the resistance to rotation becames sufficiently great, the ratchet ring Q will be rotated in the back head and the finger e will force the valve w in a direction to open communication between the passages ai and y, and thus admit fluid pressure to the chamber t to force the diaphragm a downwardly, which will apply pressure to the brake discs and either lock the rotatable brake rod e against rotation or permit slow rotation of the brake rod in the sleeve g, thus preventing or checking the operation of the feeding element. The valve w is preferably provided with differential pressure areas formed by the enlarged head 4l and the lsmaller head 5 so that when the resistance to rotation of the drill steel is again reduced sufliciently and the automatic rotation device assumes normal operation, the fluid pressure against the enlarged head 4 of the valve will restore the valve to normal posi-- tion as indicated in the figures, and cut 0E the supply of pressure to the chamber t. A vent 6 is preferably provided in the back head It, opposite the outer end of the smaller head 5 of the valve fw, through which vent pressure fluid is exhausted from the chamber t past the head 5 after the valve w is returned to its normal position. Y

It is to be assumed throughout the operation yof the machine described, that the operator retains his hand on the rotation handle a., so that the entire machine is prevented from rotating bodily about the pointer X and by this means, the operator holds the entire machine against bodily rotation and sufficient increase in resistance to rotation of the drill steel will then carry the rotation ratchet ring Q, against the valve 'w as described and automatically apply the braking device to the feeding element.

I claim:

l. In a fluid actuated rock drill having automatic rotation for the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one of said members being con-- nected to said cylinder, a fluid actuated brake associated with said feeding element for checking and preventing the relative movement of said members, and automatic means for controlling the operation of said brake in accordance with the resistance to rotation encountered by the drill steel.

2. In a liuid actuated rock drill having automatic rotation for the drill steel, the combination of a cylinder, a fiuid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable vwith one of said members and engaging the other member and a fluid actuated brake for checking and preventing rotation of said brake rod in accordance with the resistance to rotation encountered by the drill steel.

3. In a fluid actuated rock drill having automatic rot-ation for the drill' steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable with one of said members and engaging the other member and a fluid actuated brake interposed between said rotatable members of the feeding element for checking and preventing rotation of said brakerod in accordance with the resistance to rotation encountered 'by the drill steel.

l. In a fluid actuated rock drill having automatic rotation for the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected. to said cylinder, a rotatable brake rod movable with one of said members and engaging the other member, a series of discs carried by one of the said relatively. movable members of the feeding element, another series of discs interposed between said first series of discs and carried bythe rotatable brake rod and fluid actuated means for forcing the discs of said series together to check or prevent rotation of the Ybrake rod in accordance with the resistance to rotation encountered by the drill steel.

5. In a fluid actuated rock drill-having automatic rotation for the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable with one of said members and engaging the other member', a luid actuated brake for preventing and checking rotation of said brake rod, and means for automatically controlling said brake in accordance with the resistance to rotation encountered by the drill steel.

6. In a fluid actuated rock drill having automatic rotation for the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable with one of said members and engaging the other member, a fluid actuated brake interposed between said rotatable members of the feeding element for checking and preventing rotation of said brake rod, and means for automatically controlling said brake in accordance with the resistance to rotation encountered by the drill steel.

7. In a fluid actuated rock drill having automatic rotation for the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable With one of said members and engaging the other member, a series of discs carried by one of the said relatively movable members of the feeding element, another series of discs interposed between the said first series of discs and carried by the rotatable brake rod, fluid actuating' means for forcing the discs of said series together to check and prevent rotation of the brake rod, and means for auto-V matically controlling said brake, in accordance with the resistance to rotation encountered by the drill steel.

8. In a fluid actuated rock drill having meansV for automatically rotating the drill steel, the combination of a cylinder, a fluid actuated feeding element having relatively movable members, one being connected to said cylinder, a rotatable brake rod movable vvith one of said members and engaging the other member, a series'of discs carried by one of said relatively movable members of the feeding element, another series of discs 'interposed between the said first series of discs and carried by the rotatable brake rod,

a plunger adapted to bear on one end of said brake rod, fluid actuated means for actuating said plunger to apply pressure to said discs to check and prevent the rotation of said brake rod, a valve controlling the admission of pressure fluid to said fluid actuated means and means associated with said automatic rotation means for controlling the movement of said valve.

In testimony whereof I have signed this specification.

FRED M. SLATER. 

